# encoding: utf-8
#
#
# This Source Code Form is subject to the terms of the Mozilla Public
# License, v. 2.0. If a copy of the MPL was not distributed with this file,
# You can obtain one at http://mozilla.org/MPL/2.0/.
#
# Contact: Kyle Lahnakoski (kyle@lahnakoski.com)
#
from __future__ import absolute_import, division, unicode_literals

from mo_dots import Data, Null, coalesce, get_module, is_sequence
from mo_future import text, transpose, xrange
from mo_logs import Log


class Matrix(object):
    """
    SIMPLE n-DIMENSIONAL ARRAY OF OBJECTS
    """
    ZERO = None

    def __init__(self, dims=[], list=None, value=None, zeros=None, kwargs=None):
        if list:
            self.num = 1
            self.dims = (len(list), )
            self.cube = list
            return

        if value != None:
            self.num = 0
            self.dims = tuple()
            self.cube = value
            return

        self.num = len(dims)
        self.dims = tuple(dims)
        if zeros != None:
            if self.num == 0 or any(d == 0 for d in dims):  # NO DIMS, OR HAS A ZERO DIM, THEN IT IS A NULL CUBE
                if hasattr(zeros, "__call__"):
                    self.cube = zeros()
                else:
                    self.cube = zeros
            else:
                self.cube = _zeros(dims, zero=zeros)
        else:
            if self.num == 0 or any(d == 0 for d in dims):  #NO DIMS, OR HAS A ZERO DIM, THEN IT IS A NULL CUBE
                self.cube = Null
            else:
                self.cube = _zeros(dims, zero=Null)

    @staticmethod
    def wrap(array):
        output = Matrix(dims=(1,))
        output.dims = (len(array), )
        output.cube = array
        return output

    def __getitem__(self, index):
        if not is_sequence(index):
            if isinstance(index, slice):
                sub = self.cube[index]
                output = Matrix()
                output.num = 1
                output.dims = (len(sub), )
                output.cube = sub
                return output
            else:
                return self.cube[index]

        if len(index) == 0:
            return self.cube

        dims, cube = _getitem(self.cube, index)

        if len(dims) == 0:
            return cube  # SIMPLE VALUE

        output = Matrix(dims=[])
        output.num = len(dims)
        output.dims = dims
        output.cube = cube
        return output

    def __setitem__(self, key, value):
        try:
            if self.num == 1:
                if isinstance(key, int):
                    key = key,
                elif len(key) != 1:
                    Log.error("Expecting coordinates to match the number of dimensions")
            elif len(key) != self.num:
                Log.error("Expecting coordinates to match the number of dimensions")

            if self.num == 0:
                self.cube = value
                return

            last = self.num - 1
            m = self.cube
            for k in key[0:last:]:
                m = m[k]
            m[key[last]] = value
        except Exception as e:
            Log.error("can not set item", e)

    def __bool__(self):
        return self.cube != None

    def __nonzero__(self):
        return self.cube != None

    def __len__(self):
        if self.num == 0:
            return 0
        return _product(self.dims)

    @property
    def value(self):
        if self.num:
            Log.error("can not get value of with dimension")
        return self.cube

    def __lt__(self, other):
        return self.value < other

    def __gt__(self, other):
        return self.value > other

    def __eq__(self, other):
        if other == None:
            if self.num:
                return False
            else:
                return self.cube == other
        return self.value == other

    def __add__(self, other):
        return self.value + other

    def __radd__(self, other):
        return other + self.value

    def __sub__(self, other):
        return self.value - other

    def __rsub__(self, other):
        return other - self.value

    def __mul__(self, other):
        return self.value * other

    def __rmul__(self, other):
        return other * self.value

    def __div__(self, other):
        return self.value / other

    def __rdiv__(self, other):
        return other / self.value

    def __truediv__(self, other):
        return self.value / other

    def __rtruediv__(self, other):
        return other / self.value

    def __iter__(self):
        if not self.dims:
            yield (tuple(), self.value)
        else:
            # TODO: MAKE THIS FASTER BY NOT CALLING __getitem__ (MAKES CUBE OBJECTS)
            for c in self._all_combos():
                yield (c, self[c])

    def __float__(self):
        return self.value

    def groupby(self, io_select):
        """
        SLICE THIS MATRIX INTO ONES WITH LESS DIMENSIONALITY
        io_select - 1 IF GROUPING BY THIS DIMENSION, 0 IF FLATTENING
        return -
        """

        # offsets WILL SERVE TO MASK DIMS WE ARE NOT GROUPING BY, AND SERVE AS RELATIVE INDEX FOR EACH COORDINATE
        offsets = []
        new_dim = []
        acc = 1
        for i, d in reversed(enumerate(self.dims)):
            if not io_select[i]:
                new_dim.insert(0, d)
            offsets.insert(0, acc * io_select[i])
            acc *= d

        if not new_dim:
            # WHEN groupby ALL DIMENSIONS, ONLY THE VALUES REMAIN
            # RETURN AN ITERATOR OF PAIRS (c, v), WHERE
            # c - COORDINATES INTO THE CUBE
            # v - VALUE AT GIVEN COORDINATES
            return ((c, self[c]) for c in self._all_combos())
        else:
            output = [[None, Matrix(dims=new_dim)] for i in range(acc)]
            _groupby(self.cube, 0, offsets, 0, output, tuple(), [])

        return output

    def aggregate(self, type):
        func = aggregates[type]
        if not type:
            Log.error("Aggregate of type {{type}} is not supported yet",  type= type)

        return func(self.num, self.cube)


    def forall(self, method):
        """
        IT IS EXPECTED THE method ACCEPTS (value, coord, cube), WHERE
        value - VALUE FOUND AT ELEMENT
        coord - THE COORDINATES OF THE ELEMENT (PLEASE, READ ONLY)
        cube - THE WHOLE CUBE, FOR USE IN WINDOW FUNCTIONS
        """
        for c in self._all_combos():
            method(self[c], c, self.cube)

    def items(self):
        """
        ITERATE THROUGH ALL coord, value PAIRS
        """
        for c in self._all_combos():
            _, value = _getitem(self.cube, c)
            yield c, value

    def _all_combos(self):
        """
        RETURN AN ITERATOR OF ALL COORDINATES
        """
        combos = _product(self.dims)
        if not combos:
            return

        calc = [(coalesce(_product(self.dims[i+1:]), 1), mm) for i, mm in enumerate(self.dims)]

        for c in xrange(combos):
            yield tuple(int(c / dd) % mm for dd, mm in calc)

    def __str__(self):
        return "Matrix " + get_module("mo_json").value2json(self.dims) + ": " + str(self.cube)

    def __data__(self):
        return self.cube


Matrix.ZERO = Matrix(value=None)


def _max(depth, cube):
    if depth == 0:
        return cube
    elif depth == 1:
        return _MAX(cube)
    else:
        return _MAX(_max(depth - 1, c) for c in cube)


def _min(depth, cube):
    if depth == 0:
        return cube
    elif depth == 1:
        return _MIN(cube)
    else:
        return _MIN(_min(depth - 1, c) for c in cube)


aggregates = Data(
    max=_max,
    maximum=_max,
    min=_min,
    minimum=_min
)


def _iter(cube, depth):
    if depth == 1:
        return cube.__iter__()
    else:
        def iterator():
            for c in cube:
                for b in _iter(c, depth - 1):
                    yield b

        return iterator()


def _zeros(dims, zero):
    d0 = dims[0]
    if d0 == 0:
        Log.error("Zero dimensions not allowed")
    if len(dims) == 1:
        if hasattr(zero, "__call__"):
            return [zero() for _ in range(d0)]
        else:
            return [zero] * d0
    else:
        return [_zeros(dims[1::], zero) for _ in range(d0)]


def _groupby(cube, depth, intervals, offset, output, group, new_coord):
    if depth == len(intervals):
        output[offset][0] = group
        output[offset][1][new_coord] = cube
        return

    interval = intervals[depth]

    if interval:
        for i, c in enumerate(cube):
            _groupby(c, depth + 1, intervals, offset + i * interval, output, group + (i, ), new_coord)
    else:
        for i, c in enumerate(cube):
            _groupby(c, depth + 1, intervals, offset, output, group + (-1, ), new_coord + [i])





def _getitem(c, i):
    if len(i)==1:
        select = i[0]
        if select == None:
            return (len(c), ), c
        elif isinstance(select, slice):
            sub = c[select]
            dims, cube = transpose(*[_getitem(cc, i[1::]) for cc in sub])
            return (len(cube),) + dims[0], cube
        else:
            return (), c[select]
    else:
        select = i[0]
        if isinstance(select, int):

            return _getitem(c[select], i[1::])
        elif select == None:
            dims, cube = transpose(*[_getitem(cc, i[1::]) for cc in c])
            return (len(cube),)+dims[0], cube
        elif isinstance(select, slice):
            sub = c[select]
            dims, cube = transpose(*[_getitem(cc, i[1::]) for cc in sub])
            return (len(cube),)+dims[0], cube
        else:
            return _getitem(c[select], i[1::])


def _zero_dim(value):
    return tuple()


def index_to_coordinate(dims):
    """
    RETURN A FUNCTION THAT WILL TAKE AN INDEX, AND MAP IT TO A coordinate IN dims

    :param dims: TUPLE WITH NUMBER OF POINTS IN EACH DIMENSION
    :return: FUNCTION
    """
    _ = divmod  # SO WE KEEP THE IMPORT

    num_dims = len(dims)
    if num_dims == 0:
        return _zero_dim

    prod = [1] * num_dims
    acc = 1
    domain = range(0, num_dims)
    for i in reversed(domain):
        prod[i] = acc
        acc *= dims[i]

    commands = []
    coords = []
    for i in domain:
        if i == num_dims - 1:
            commands.append("\tc" + text(i) + " = index")
        else:
            commands.append("\tc" + text(i) + ", index = divmod(index, " + text(prod[i]) + ")")
        coords.append("c" + text(i))
    output = None
    if num_dims == 1:
        code = (
            "def output(index):\n" +
            "\n".join(commands) + "\n" +
            "\treturn " + coords[0] + ","
        )
    else:
        code = (
            "def output(index):\n" +
            "\n".join(commands) + "\n" +
            "\treturn " + ", ".join(coords)
        )

    fake_locals = {}
    exec(code, globals(), fake_locals)
    return fake_locals["output"]


def _product(values):
    output = 1
    for v in values:
        output *= v
    return output


def _MIN(values):
    output = None
    for v in values:
        if v == None:
            continue
        elif output == None or v < output:
            output = v
        else:
            pass
    return output


def _MAX(values):
    output = Null
    for v in values:
        if v == None:
            continue
        elif output == None or v > output:
            output = v
        else:
            pass
    return output
